Carotid Ultrasound to Predict Fluid Responsiveness

Abstract

Objectives-To perform a systematic review of the accuracy of carotid ultrasound measures in determining volume responsiveness in adults. Methods-We conducted a systematic review of Ovid MEDLINE and Scopus from conception until January 1, 2019. Two independent reviewers used an iterative process to identify relevant articles and abstract information from them. The quality and risk of bias were assessed with the Quality Assessment of Diagnostic Accuracy Studies version 2 tool. Results-We identified 17 relevant articles with 956 patients. The 2 most frequently cited carotid measures of fluid responsiveness were corrected flow time and peak velocity or change in peak velocity with respiration (ΔCDPV). Accordingly, the diagnostic characteristics of corrected flow time in these studies varied widely, with sensitivities from 60% to 73%, specificities from 82% to 92%, and areas under the receiver operating characteristic curves from 0.75 to 0.88. Optimal cutoff values for ΔCDPV ranged from 9.1% to 14%, with areas under the receiver operating characteristic curves from 0.81 to 0.91, sensitivities from 73% to 86%, and specificities from 78% to 86%. Other measures, such as carotid blood flow and carotid diameter, had limited data to support their use. Heterogeneity of the studies prohibited a meta-analysis. Most studies had a moderate risk of bias and high applicability. Conclusions-Preliminary research suggests that carotid ultrasound measures may be useful adjunct measures of fluid status; however, they should not be interpreted as absolute and should be placed in a clinical context. The most welldefined and supported measure currently is ΔCDPV, with cutoffs from 9% to 14%. Corrected flow time shows promise, because of heterogeneity of how this value is measured, an optimal cutoff has not been established.

Minimizing Measurement Variability in Carotid Ultrasound Evaluations

“…To the Editor: We read with great interest the systematic review by Beier and colleagues entitled "Carotid Ultrasound to Predict Fluid Responsiveness." 1 Congratulating the authors on their excellent review of the literature and meticulous analysis, we agree with their conclusion supporting the use of carotid ultrasound in the assessment of volume responsiveness. Although the authors recognize the utility of metrics such as the change in the peak carotid velocity and carotid corrected flow time, measurement variability remains an obstacle for wider use of these parameters in daily clinical work.…”

Carotid artery velocity time integral and corrected flow time measured by a wearable Doppler ultrasound detect stroke volume rise from simulated hemorrhage to transfusion

“…Inferring change in stroke volume (SV) is the bedrock of functional hemodynamic monitoring [ 1 , 2 ]. Yet measuring SV change (SV ∆ ) is clinically challenging, so surrogates like the common carotid artery Doppler pulse have been proposed [ 3 , 4 ] with some conflicting data [ 5 ]. We contend that statistically-inadequate beat sampling coupled with variation introduced by the respiratory cycle are important arbiters of inconsistent clinical research [ 6 ].…”

Inferring the Frank–Starling Curve From Simultaneous Venous and Arterial Doppler: Measurements From a Wireless, Wearable Ultrasound Patch

“…Association between changing SV and common carotid arterial Doppler in critically ill patients has been demonstrated (18,19). This is noted for both total flow and corrected systolic flow time as a surrogate for SV and supported by a recent systematic review (28). Nevertheless, there are conflicting data on this topic (29); there are potentially many sources of error that could explain discrepant results including variability in devices used, patient demography, and protocol differences (30,31).…”